JP2002296348A - Onboard radar apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an onboard radar apparatus which can decide the position of an obstacle from a vehicle, without having to provide a transmission means and by using a radio signal which can be received by the vehicle. SOLUTION: A GPS signal is received by a receiving means, which is composed of right circularly polarized wave antenna and a left circularly polarized wave antenna, direct waves and reflected waves are separated, and the path length of the reflected waves is found. Using a GPS positioning operation, a linear distance up to a GPS satellite, the position of the vehicle and the position of the GPS satellite are obtained, the position of the vehicle and the position of the satellite are used as a focus, and the position on the surface of a spheroid which uses the path length of the reflected waves as a major axis is used as a candidate for a reflecting point. The candidate for the reflecting point is found, regarding a plurality of positions on the vehicle or a plurality of positions on the satellite, and the common contact face or the common intersection point of the plurality of spheroids is decided as the position of the obstacle which is a reflecting position.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radar device, and more particularly, to a vehicle-mounted radar device capable of determining the position of an obstacle in a moving body such as a vehicle.

[0002]

2. Description of the Related Art In recent years, an on-vehicle radar device has been provided as one of driving support systems for the purpose of safely driving a vehicle. The on-vehicle radar device uses, for example, a millimeter wave band radio wave to measure a distance to an obstacle, a relative speed, and the like. Generally, an on-vehicle radar device includes a transmitting unit for transmitting a radio wave and a receiving unit for a radio wave. The in-vehicle radar device transmits the radio wave forward, receives the reflected wave from the obstacle ahead, compares the transmitted signal with the received signal, and determines the relative distance and relative speed to the obstacle ahead. Measure.

On the other hand, GPS (Global Positioning System)
m), a system that receives a signal from a GPS satellite by a vehicle or the like to measure a distance from the satellite to the vehicle, calculate a position on the vehicle side, obtain satellite position information, and the like is also known. ing. The GPS signal includes navigation data such as satellite position information, and also includes a ranging signal for obtaining the arrival time of the signal, whereby the vehicle measures the distance to the satellite and performs positioning calculation. It is possible.

[0004]

As described above, the conventional on-vehicle radar device requires a radio wave transmitting means and a receiving means, and depending on the configuration of the transmitting means, the radio wave signal which can be used as the on-vehicle radar device is required. The transmission frequency and transmission power are determined.

[0005] Further, the conventional on-vehicle radar device is designed to specify the transmission direction of the radio wave or to suppress the interference of the radio wave.
The cost is high because the beam to be transmitted needs to be aperture-scanned and the frequency of usable radio waves is high, which hinders its spread.

[0006] The present invention has been made in view of such problems. That is, an object of the present invention is to provide an on-vehicle radar device that can determine the position of an obstacle in a vehicle by using a radio signal that can be received by the vehicle without including a transmitting unit. And

[0007]

According to the present invention, a receiving means for receiving a radio signal arriving from a transmitter and a path length of a reflected wave are obtained based on the received radio signal. Reflected wave measuring means, positioning means for performing a positioning operation to obtain a positioning position, transmitter position obtaining means for obtaining a transmitter position, a path length of the obtained reflected wave, and a positioning position obtained by a positioning operation; And a reflection position estimating means for obtaining an estimated position of the reflection position of the reflected wave based on the transmitted transmitter position. It is possible to obtain the estimated position of the reflection position based on the path length of the reflected wave obtained based on the radio signal received from the transmitter, the positioning position, and the transmitter position. Therefore, this radar device does not have a transmission means, and does not have an obstacle (ie,
The estimated position of the reflected wave can be determined.

[0008] For example, the reflection position estimating means uses the positioning position obtained by the positioning calculation and the acquired transmitter position as the focal points, and sets the position of the surface on the spheroid having the path length of the reflected wave as the major axis as the estimated position. (Claim 2).

If the reflection position estimating means is configured to obtain a plurality of spheroids as estimated positions at at least two or more different positions with respect to the positioning position and / or the transmitter position,
The on-vehicle radar device further includes calculation means for determining a reflection position by determining a common contact surface or intersection point for at least two or more of the plurality of spheroids, and determining the identified position as the reflection position. It can be configured (claim 3). By identifying the reflection position, an accurate reflection position is obtained.

According to a fourth aspect of the present invention, the radio signal is a circularly polarized wave signal, and the receiving means includes a right-handed circularly polarized wave receiving element and a left-handed circularly polarized wave receiving element. Prepare. In this case, the reflected wave measuring means determines whether the received radio signal is received based on whether the received radio signal is received by the right-handed circularly polarized wave receiving element or the left-handed circularly polarized wave receiving element. It is possible to recognize whether the wave is a direct wave or a reflected wave.

According to a fifth aspect of the present invention, in the on-vehicle radar device, the receiving means includes a plurality of receiving elements, and the on-vehicle radar device further includes:
Means are provided for determining the arrival direction of the reflected wave. In this case, the reflection position estimating means can limit the range of the estimated position based on the obtained direction of arrival, and can set the position of the limited range as the estimated position.

[0012] In the vehicle-mounted radar device according to claim 6, the transmitter is a GPS satellite, and the radio signal is a GPS signal. In this case, the reflected wave measuring means can determine the path length of the reflected wave based on the arrival time of the ranging signal included in the GPS signal (claim 7). Also, the positioning means,
The positioning position can be obtained by performing GPS positioning (claim 8). Further, the transmitter position acquiring means can acquire the transmitter position from the received GPS signal (claim 9).

According to a tenth aspect of the present invention, the transmitter is a base station of a radio communication system. The wireless signal is preferably a spread spectrum modulated signal based on the CDMA system (claim 11). In this case, the reflected wave measuring means includes a positioning position, a transmitter position, and a time difference between a direct wave and a reflected wave obtained by performing inverse spread spectrum processing on the received wireless signal at different phase positions. The path length of the reflected wave can be obtained based on the above (claim 12).

[0014] Further, the transmitter position obtaining means can obtain the transmitter position from the received radio signal. Alternatively, the transmitter position obtaining means may be configured by a storage device in which the position of the transmitter is stored (claim 14).

[0015] In the vehicle-mounted radar device according to claim 15, the transmitter is a broadcasting station. In this case, the transmitter position obtaining means can also obtain the transmitter position from the received wireless signal (claim 16). Alternatively, the transmitter position obtaining means may be configured by a storage device in which the position of the transmitter is stored (claim 17).

[0016]

FIG. 1 is a block diagram showing the configuration of an on-vehicle radar device 100 according to a first embodiment of the present invention. FIG. 2 is a diagram illustrating an operation environment of the on-vehicle radar device 100. The on-vehicle radar device 100 includes a vehicle 21
1, a transmitter 21 which is a GPS satellite.
2 to determine the position of the obstacle 201. FIG. 3 shows an operation environment when the positions of the vehicle 211 and the transmitter 212 have moved with the passage of time from the state of the operation environment in FIG.

As shown in FIG. 2, a transmitter (GPS satellite)
212 transmits a radio signal modulated using spread spectrum to the ground. This wireless signal includes the vehicle 2 on the ground
The path 213 directly reaching the vehicle 11 (this will be referred to as a zero-time reflection path) and the obstacle 201 near the vehicle 211
It is assumed that there is a multipath such as a path 214 that reflects once to the vehicle 211 and arrives at the vehicle 211 (this is a single reflection path).

The operation of the on-vehicle radar device 100 shown in FIG. 1 will be described below with reference to FIGS. Radio signals from GPS satellites are right-handed circularly polarized in order to reduce the effects of multipath. Therefore, right-handed circularly polarized antennas are usually used for their reception. The antenna of the radar device 100 includes a right-handed circularly polarized antenna 111 and a left-handed circularly polarized antenna 112.

Therefore, in the signal received by the right-handed circularly polarized antenna 111, the intensity of the direct wave and the reflected wave (even-numbered reflected wave) reflected even number times by an obstacle or the like increases, while the left-handed circular wave is reflected. In the signal received by the polarization antenna 112,
The intensity of a reflected wave that is reflected an odd number of times by an obstacle or the like (an odd number of times a reflected wave) increases.

The signal received by right-handed circularly polarized antenna 111 is input to demodulation section A113. Demodulation unit A113
Performs path separation by inverse spectrum spreading on the right-handed circularly polarized reception signal, and sends the demodulation result of the 0-time reflected wave and timing information including the arrival time to the arithmetic unit 115.

The signal received by left-handed circularly polarized antenna 112 is input to demodulation section B114. Demodulation unit B114
Separates the path of the left-hand circularly polarized reception signal by inverse spectrum spreading, and sends the result of demodulation of the once reflected wave and timing information including the arrival time to the arithmetic unit 115.

The arithmetic unit 115 measures the distance between the transmitter 212 and the vehicle 211 and determines the position and speed of the vehicle 211 based on the demodulation result and the timing information input from the demodulation units A113 and B114. Calculation and data demodulation processing of satellite position information and the like are executed.

Next, referring to the flowchart of FIG.
Processing for determining the position of the obstacle 201, which is performed by the arithmetic unit 115, will be described. First, in step S111, reception of a radio signal by the right-handed circularly polarized antenna 111 and the left-handed circularly polarized antenna 112 is performed. In step S121, based on the output from the demodulation unit A113, it is determined whether the demodulation of the signal on the reflection path for zero times is possible for a plurality of transmitters (that is, a plurality of GPS satellites). As a result, if demodulation is possible (S121: YES), the arithmetic unit 115 performs a data demodulation process based on the output from the demodulation unit A113, thereby returning the zero-time reflected wave path 213 (see FIG. 2). (That is, a straight-line distance from the transmitter 212 to the vehicle 211) is calculated, and a positioning calculation for determining the position of the vehicle 211 is performed (S122). If it is determined in step S121 that demodulation of the signal is not possible (S121: NO), the process returns to S111, and a wireless signal is received.

Next, in step S131, the demodulation unit B1
Based on the output from 14, it is determined whether the signal from the transmitter 212 can demodulate the signal in the single reflection path. As a result, if demodulation is possible (S13
1: YES), the demodulation unit B114 in the arithmetic unit 115
By performing data demodulation processing based on the output from
The distance for the reflected wave path 214 (see FIG. 2) (ie, the total distance of the distance from the transmitter 212 to the obstacle 201 and the distance from the obstacle 201 to the vehicle 211) is calculated (S132). If it is determined in step S131 that demodulation of the signal is impossible, (S13
1: NO), the process returns to S111, and a wireless signal is received.

Next, in step S133, the arithmetic unit 115, the position _{P 0} and the position _{P 1} of the vehicle 211 as a focal point, spheroid 215 to the path length of the single reflection path 214 and the major axis of the transmitter 212 The point on the surface of the spheroid 215 is set as a reflection point candidate.

Next, in step S141, it is determined whether or not the reflection point can be identified. Spheroid 215
Is obtained for a plurality of transmitters (GPS satellites), or the processing from S111 is performed again after it is determined that the identification is not possible in step S141, and the transmitter after a lapse of time as shown in FIG. When a spheroid 225 that is a reflection point candidate is obtained based on the positional relationship between 212 and the vehicle 211, a process for identifying the reflection point can be performed. The process of identifying a reflection point can be performed, for example, by finding a close common tangent surface or intersection point for a plurality of spheroids that are reflection point candidates. The position of the obstacle 201 is determined as a reflection point or a reflection surface by performing identification using information on the reflection point candidate 215 and the reflection point candidate 225, or further using information on an additional spheroid.

If identification is possible (S141: YES), the process proceeds to step S142, and the identified reflection surface or reflection point is displayed on the display unit 116 as an obstacle. Is notified to the user. If it is determined in step S141 that identification cannot be performed (S141: NO), the process proceeds to step S111.
And the wireless signal is received again.

In the on-vehicle radar device 100 shown in FIG. 1, the antenna is composed of a right-handed circularly polarized antenna 111 and a left-handed circularly polarized antenna 112. An integrated antenna may be used. In the on-vehicle radar device 100, G
Since the radio signal from the PS satellite is right-handed circularly polarized,
Although a right-handed circularly polarized antenna and a left-handed circularly polarized antenna are used, if the transmission signal on the transmitter side is of another polarization type, by using an antenna of a corresponding polarization type, The functions of the on-vehicle radar device 100 described above can be realized.

Next, FIG. 5 is a block diagram showing the configuration of an on-vehicle radar device 200 according to a second embodiment of the present invention. FIG. 6 shows the operation unit 12 of the on-vehicle radar device 200.
5 is a flowchart illustrating a process for determining a position of an obstacle, which is executed by the control unit 5; 5 and 6, a block diagram of FIG. 1 relating to the above-described first embodiment,
The same components and processing steps as those in the flowchart of FIG. 4 are denoted by the same reference numerals, and detailed description thereof will be omitted. FIG. 7 is a diagram illustrating an operation environment of the on-vehicle radar device 200. The on-vehicle radar device 200 is assumed to be mounted on the vehicle 231.

As shown in the block diagram of FIG. 5, the on-vehicle radar device 200 includes a left-handed circularly polarized array antenna 122 composed of a plurality of left-handed circularly polarized antennas and a plurality of demodulation units provided correspondingly. And a demodulation unit B124. Each antenna element of the left-handed circularly polarized wave array antenna 122 is connected to a corresponding demodulation unit B.

Each demodulation section B demodulates a signal from the corresponding antenna element, and performs a one-time reflection path 234 (see FIG. 7).
Is output to the arithmetic unit 125. As described above, the left-handed circularly polarized wave array antenna 122 and the demodulation unit B124 are configured to be able to simultaneously execute a plurality of demodulations of a single reflection path.

Next, with reference to FIG. 6, a process for determining the position of an obstacle, which is executed by the arithmetic unit 125, will be described. After calculating the distance and the like of the zero reflection path 233 in Step 122, in Step S131, it is determined whether or not the single reflection path can be demodulated based on the output from the demodulation unit B124. You. As a result, if demodulation is possible (S131: YES), the distance of the first reflection path 234 is calculated (S133).

Next, in step S133, the transmitter 23
The position _{P 11} of the second position _{P 10} and the vehicle 231 and the focal point,
A reflection point candidate 235, which is a spheroid whose major axis is the path length of the single reflection path 234, is calculated. Next, step S
In 134, for example, the arrival direction 216 of the one-time reflection path 234 of the transmitter 232 is estimated by performing an estimation method such as DFT operation on the demodulated waveform from each demodulation unit B of the demodulation unit B 124. Then, of the reflection point candidates 235, only the portion that matches the arrival direction 216 is calculated as the limited reflection point candidate 217 (S134).

In step S141, as in the first embodiment, a change in the position of the vehicle 231 or a change in the position of the transmitter 232, or the position of another transmitter when the positions of a plurality of transmitters are obtained. , The reflection surface or the reflection point is identified by finding the close common tangent surface or intersection point for the plurality of limited reflection point candidates. That is,
Here, the position of the obstacle 201 is determined. Next, in step S142, the identified obstacle 2
The position of 01 is displayed on the display unit 116 of the on-vehicle radar device 200, and the user is notified.

As described above, in the case of the second embodiment, the calculation of the common tangent surface or the intersection is performed only in the direction of arrival of the single reflection path, so that the process of calculating the common tangent surface or the intersection is performed. It is possible to reduce the amount of data used for the above. This allows for faster processing and higher accuracy. It should be noted that the antenna in the second embodiment may be a single antenna that is a combination of a right-handed circularly polarized antenna and a left-handed circularly polarized antenna. In the case of the system, the function of the above-described on-vehicle radar device 200 can be realized by using a polarization type antenna corresponding to the system.

The first and second embodiments described above are examples in which a radio signal from a GPS satellite is used as a signal from which the arrival time of a radio signal, position information on the transmitter side, and the like can be obtained. Was. On the other hand, in other wireless communication systems and broadcasting, there are wireless signals that are constantly transmitted regularly for synchronization acquisition, provision of position information, provision of time information, and the like. For example, CDMA (Code Division Multiple)
In a synchronization channel in the Access) system, spread spectrum modulation is performed using a spreading sequence common to each base station, and a signal without data modulation is always transmitted. It is assumed that the transmitter used by the on-vehicle radar device 300 of the third embodiment is a base station of a wireless communication system using such a CDMA system. This wireless communication system is, for example, a CDMA mobile communication system, and is hereinafter referred to as a wireless communication system A.
FIG. 8 shows a vehicle-mounted radar device 30 according to a third embodiment.
FIG. 3 is a block diagram illustrating a configuration of a zero.

The flow of operation for determining the position of an obstacle in the on-vehicle radar device 300 is the same as the flow chart of the on-vehicle device 100 shown in FIG. The operation environment will also be described with reference to FIGS. That is, it is assumed that the on-vehicle radar device 300 is mounted on the vehicle 211 and the transmitter 212 is a base station of the wireless communication system A. Therefore, in this case, the transmitter 212 itself does not move.

In FIG. 8, an antenna 131 receives a signal of a synchronization channel from a transmitter (base station) 212. The signal received by the antenna 131 is
Is input to The demodulation unit 132 detects timing information (for example, a time difference) between the 0-time reflection path and the 1-time reflection path by separately despread demodulating the received signals having different phases due to the multipath, and calculates the operation unit 135. Output to

The position information acquisition unit 137 is, for example, a mobile terminal of the radio communication system A, and is a transmitter (base station) 21.
2 is obtained and output to the calculation unit 135. Note that the position information acquisition unit 137 may be a storage device in which the position of each transmitter (each base station) is stored in advance.

The operation unit 135 includes transmitter position information from the position information acquisition unit 137, timing information between the 0-time reflection path and the 1-time reflection path from the demodulation unit 132, and the vehicle position from the positioning means (not shown). Using the information, the reflection point candidate 215
Is calculated (step S133 in FIG. 4). Here, the positioning means includes a means for performing positioning based on three or more pieces of transmitter position information and the timing of the corresponding zero-time reflection path, a GPS receiver, and the like. The major axis of the spheroid (the reflection point candidate 215) (that is, the path length of the single reflection path 214) is based on the transmitter position information, the vehicle position information, and the timing between the zero reflection path and the single reflection path. Information (ie, the single reflection pass 21)
Information on the difference between the path length of No. 4 and the path length of the zero-time reflection path 213)
And can be obtained from Further, by changing the position of the vehicle 211 or, when the positions of a plurality of transmitters are obtained, according to the positions of the other transmitters, a plurality of reflection point candidates are obtained, by obtaining a close common tangent surface or intersection.
The reflection surface or the reflection point is identified (step S in FIG. 4).
141). The identified reflection surface or reflection point is displayed on the display unit 1.
16 and the user is notified.

The on-vehicle radar device 3 according to the third embodiment described above.
00 is not a base station of the wireless communication system A, but a broadcast station that transmits position information, or a broadcast station in which position information is stored inside the on-vehicle radar device 300,
Similar processing can be performed. Further, the same processing can be realized not only when the transmitter is a ground station but also when it is a satellite station.

FIG. 9 shows a radio communication system A according to a fourth embodiment of the present invention, similar to the on-vehicle radar device 300.
Radar system 400 using a base station as a transmitter
It is a block diagram showing the structure of. 9, the same components as those in the block diagram of FIG. 8 are denoted by the same reference numerals, and detailed description will be omitted. The flow of the obstacle position determination process in the on-vehicle radar device 400 is the same as that of the on-vehicle radar device 200 in the second embodiment shown in FIG. In addition, the on-vehicle radar device 40
The operation environment of the operation of 0 will be described with reference to FIG. That is, the on-vehicle radar device 400 is
It is assumed that the transmitter 232 is a base station of the wireless communication system A.

The array antenna 141 is configured by arranging a plurality of antennas. Each antenna element of the array antenna 141 outputs a received signal to each demodulation unit of the demodulation unit 142.

The position information acquisition unit 137 is, for example, a mobile terminal of the radio communication system A, and is a transmitter (base station) 23.
2 is obtained and input to the calculation unit 145. Note that the position information acquisition unit 137 may be a storage device in which the position of each transmitter (each base station) is stored in advance.

The calculation unit 145 receives the transmitter position information from the position information acquisition unit 137, the timing information (for example, the time difference) between the zero reflection path 233 and the single reflection path 234, and the position information from the positioning means (not shown). The reflection point candidate 235 (FIG. 7) is calculated using the vehicle position information (FIG. 6, step S13).
3). Next, the DFT of each demodulated signal of demodulation section 142 is performed.
The arrival direction 216 of the one-time reflection path 234 for the transmitter 232 is estimated using an estimation method such as an arithmetic operation, and further, the limited reflection point is obtained by limiting the reflection point candidate 235 to a portion that matches the arrival direction 216. The candidate 217 is calculated (Step S134 in FIG. 6).

As in the case of the third embodiment,
The change in the position of the vehicle 231 or, if the positions of a plurality of transmitters can be obtained, the positions of the other transmitters are used to determine the proximity common tangent surface or intersection with respect to the plurality of limited reflection point candidates. Identification of a surface or a reflection point is performed (step S141 in FIG. 6). The identified reflection surface or reflection point is displayed on the display unit 116, and the user is notified.

As described above, in the case of the fourth embodiment, the calculation of the common tangent surface or the intersection is performed only in the direction of arrival of the single reflection pass. It is possible to reduce the amount of data used for the above. This allows for faster processing and higher accuracy.

In the on-vehicle radar device 400 according to the fourth embodiment described above, the transmitter is not a base station of the radio communication system A, but a broadcasting station for transmitting position information, or the position information is stored inside the on-vehicle radar device 400. The same processing can be performed by the broadcast station that has been set. Further, the same processing can be realized not only when the transmitter is a ground station but also when it is a satellite station.

[0049]

As described above, according to the present invention, it is possible to realize an on-vehicle radar device which does not require a transmitting means for transmitting a radio signal for measurement. Since no transmitting means is required, the cost can be significantly reduced. In addition, since a commonly used wireless signal is used as a transmission signal, the cost of components in receiving means such as an antenna and a demodulation unit can be kept low.

Since it is not necessary for the radar device to have a transmitting means, there is no need to secure a radio frequency for a transmission signal. Therefore, it is possible to contribute to the effective use of the radio frequency.

The transmission signal used in the on-vehicle radar device of the present invention is a signal of a GPS satellite, a signal of a base station of a radio communication system, or the like. Since the direction of arrival of the transmission signal is distributed over a wide range, the radar signal is used. As a result, a wide directivity can be obtained. This means that the on-vehicle radar device of the present invention can determine obstacle positions in a wide range of directions.
The obtained obstacle position can be used for any purpose such as identifying the position of a shield that interferes with radio wave reception in the vehicle, including use for safe driving of the vehicle.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of an on-vehicle radar device according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating an operation environment of the on-vehicle radar device according to the first embodiment.

FIG. 3 is a diagram illustrating an operation environment of the on-vehicle radar device according to the first embodiment, which is another example different from FIG. 2;

FIG. 4 is a flowchart illustrating an operation of determining the position of an obstacle in the on-vehicle radar device according to the first embodiment.

FIG. 5 is a block diagram illustrating a configuration of an on-vehicle radar device according to a second embodiment of the present invention.

FIG. 6 is a flowchart illustrating an operation of determining the position of an obstacle in the on-vehicle radar device according to the second embodiment.

FIG. 7 is a diagram illustrating an operation environment of a vehicle-mounted radar device according to a second embodiment.

FIG. 8 is a block diagram illustrating a configuration of an on-vehicle radar device according to a third embodiment of the present invention.

FIG. 9 is a block diagram illustrating a configuration of an on-vehicle radar device according to a third embodiment of the present invention.

[Explanation of symbols]

 111 Right-handed circularly polarized antenna 112 Left-handed circularly polarized antenna 113, 114 Demodulation unit 115 Operation unit 116 Display unit 201 Obstacle 212 Transmitter 213 Zero reflection path 214 One reflection path 215 Reflection point candidate

Claims (17)

[Claims] 1. A receiving means for receiving a radio signal arriving from a transmitter, a reflected wave measuring means for obtaining a path length of a reflected wave based on the received radio signal, and a positioning operation for obtaining a positioning position Positioning means, transmitter position obtaining means for obtaining the position of the transmitter, the obtained path length of the reflected wave, the positioning position obtained by the positioning calculation, and the obtained transmitter position based on the obtained An on-vehicle radar device, comprising: reflection position estimating means for obtaining an estimated position of a reflection position of a reflected wave. 2. The reflection position estimating means calculates a position of a surface on a spheroid having a position determined by the positioning operation and the acquired transmitter position as focal points and a path length of the reflected wave as a long axis. The in-vehicle radar device according to claim 1, wherein the estimated position is set. 3. The reflection position estimating means obtains a plurality of spheroids as the estimated position at at least two or more different positions with respect to the positioning position and / or the transmitter position. Further, calculating means for identifying the reflection position by obtaining a common tangent surface or intersection point with respect to at least two or more of the plurality of spheroids, and determining the identified position as the reflection position, The on-vehicle radar device according to claim 2, wherein 4. The radio wave signal is a circularly polarized wave signal, the receiving means includes a right-handed circularly polarized wave receiving element and a left-handed circularly polarized wave receiving element, and the reflected wave measuring means. The received radio signal is a direct wave based on whether the received radio signal is received by the right-handed circularly polarized wave receiving element or the left-handed circularly polarized wave receiving element. The on-vehicle radar device according to any one of claims 1 to 3, wherein the on-board radar device recognizes whether there is a reflected wave or a reflected wave. 5. The receiving means includes a plurality of receiving elements, and the on-vehicle radar device further includes means for determining an arrival direction of the reflected wave based on signals from the plurality of receiving elements. The reflection position estimating means limits the range of the estimated position based on the obtained direction of arrival, and sets the position of the limited range as the estimated position. An in-vehicle radar device according to any one of claims 1 to 4. 6. The apparatus according to claim 1, wherein the transmitter is a GPS satellite, and the wireless signal is a GPS signal.
An in-vehicle radar device according to any one of claims 1 to 5. 7. The on-vehicle radar device according to claim 6, wherein the reflected wave measuring unit obtains a path length of the reflected wave based on an arrival time of a ranging signal included in the GPS signal. . 8. The on-vehicle radar device according to claim 6, wherein the positioning unit obtains the positioning position by performing GPS positioning. 9. The on-vehicle radar device according to claim 6, wherein the transmitter position obtaining unit obtains the transmitter position from the received GPS signal. 10. The on-vehicle radar device according to claim 1, wherein the transmitter is a base station of a wireless communication system. 11. The on-vehicle radar device according to claim 10, wherein the radio signal is a spread spectrum modulation signal based on a CDMA system. 12. The reflected wave measuring means is configured to determine a position of the positioning position, a position of the transmitter, and a direct wave and a reflected wave obtained by performing inverse spread spectrum processing on the received radio signal at different phase positions. 2. The path length of the reflected wave is obtained based on the time difference between the two.
2. The on-vehicle radar device according to 1. 13. The on-vehicle radar device according to claim 10, wherein said transmitter position obtaining means obtains said transmitter position from said received radio signal. 14. The on-vehicle radar device according to claim 10, wherein said transmitter position acquisition means comprises a storage device in which the position of said transmitter is stored. 15. The on-vehicle radar device according to claim 1, wherein the transmitter is a broadcasting station. 16. The on-vehicle radar device according to claim 15, wherein said transmitter position obtaining means obtains said transmitter position from said received radio signal. 17. The on-vehicle radar device according to claim 15, wherein said transmitter position acquisition means comprises a storage device in which the position of said transmitter is stored.